1. Field of the Invention
This invention relates to a method of measuring the accuracy, etc. of an anamorphic lens which is different in power in the vertical direction and in the horizontal direction (including toric lens, cylindrical lens, etc.) and to an apparatus for carrying out the method.
2. Description of the Prior Art
Heretofore, there has been often used a method employing interference fringes as means for measuring the accuracy of a lens. Particularly in a spherical lens, there has been generally adopted a method in which a Newton plate is used as a handy measuring method.
However, in a case that the anamorphic lens is tested, it is difficult to make a Newton plate, and also it was difficult to determine whether the accuracy of a lens to be processed is coincident with a designed value.